Introduction

The article will describe factors of influence on return to work RTW and evidence-based interventions that enhance return to work (RTW) after sick leave due to common mental health disorders (CMD). First the concepts of both RTW and CMD are outlined. Second, the sense of urgency for effective RTW interventions for workers with CMD is briefly described. Third, a variety of predictors of RTW are presented with respect to the disorder, personal factors, and environmental factors. Lastly, a brief description of usual care and an overview of effective RTW interventions will be provided. A final paragraph will provide some conclusions as to which measures at what level appear to be effective in return to work after sick leave due to mental health disorders.

Definitions: What is return to work after mental ill health?

This article will focus on individuals returning to work with common mental health disorders with both work-related and non-work related causes. Comon mental health problems include for example depression, anxiety, adjustment disorder and other stress-related disorders.

Return to work (RTW) can be defined as: “Resuming work tasks/work hours after a period of sick leave”. Although definitions of RTW vary according to disciplines or socio-legal contexts, most researchers use criteria such as work status (present/absent from work), number of hours worked or time until resuming contractual hours (with equal earnings. A few studies have recently paid more attention to the quality of RTW (e.g. work functioning and the sustainable RTW) [1].

Why is ‘return-to work’ after sick leave due to mental ill health an important issue?

According to the OECD mental health at the workplace is considered an upcoming priority challenge for the labour market [2]. The costs of mental ill-health for the individuals concerned, employers and society at large are very high. A conservative estimate from the International Labour Organisation (ILO) put them at 3-4% of the gross domestic product in the EU. Most of these costs do not occur within the health sector.

Common mental disorders (CMD) are highly prevalent in the working population. For example, the 12-month prevalence for having any depressive, anxiety or alcohol related problem is 9% in the European working population [3]. For less severe complaints such as burnout these rates can even reach 16% [4][5].

People with CMD often experience difficulties in meeting work demands with respect to mental performance (e.g. concentrating), interpersonal tasks (e.g., handling emotions) or handling work pressure (e.g. keeping up work pace or quality, energy regulation setting one’s personal boundaries) [6][7].

CMD often result in long term sick leave spells, and the overall employment rates of people with CMD is around 10-15% lower than among people with no mental disorder (2). In addition, the OECD research [2]shows that while the prevalence of mental ill-health overall is not rising, an increase in disability benefit claims and absenteeism because of mental ill-health is visible. Furthermore, 20 to 30% of the workers with CMD who return to work experience recurrent sickness absence due to mental health problems [8]. Considering the individual suffering and economic burden associated with long-term sick leave for both employers and society, it is important that effective RWT interventions are implemented.

Factors of influence on RTW after sick leave due to mental health problems

In order to develop effective interventions and screen for cases at risk for long-term sick leave it is important to know what factors predict RTW. Empirical evidence underlines the multifaceted nature of RTW and has demonstrated the impact of disorder characteristics (e.g., severity of depressive symptoms), other individual characteristics (e.g., age), and environmental factors (e.g., supervisor behavior) on RTW. Below we present the predictors of RTW in relation to each of these levels that have been reported in systematic reviews [9][10][11][12]. It is important to note that predictors can vary according to the type of disorder or the OSH legislation.

Disorder/ health

Reviews [9][10][11][12] conclude that more severe symptoms, longer duration of a mental ill health episode and co-morbid physical or mental health problems predict unfavorable RTW outcomes. In addition, compared with other common mental health disorders, employees with a major depression also have lower chances for successful RTW. Especially the relation between duration of depressive symptoms and functioning in work stresses the importance of a rapid treatment of these mental ill health symptoms.

Symptom reduction contributes to better RTW, in a way that symptoms’ improvement is followed, after a substantial time lag, by an improvement of work functioning [2]. However it is important to note that other factors play an important role as well. For example, among depressed employees only 10% of successful RTW could be explained by symptom reduction [13]. In addition, treatment that is adequate in reducing symptoms usually have limited or no effect on occupational outcomes such as RTW [2][14]. So, it seems that symptom reduction is no guarantee for RTW. Several intervention studies indeed show that symptom recovery and the process of RTW are partly independent [15][16][17][18]. This means that for individuals who experience similar symptom levels, one person might return to work while the other person will not.

Personal

Reviews [9][10][11][12] have related several demographic characteristics to lower RTW chances such as: higher age (e.g. above 50), lower education, a prior history of sick leave, and marital status (widowed, divorced or single). Results on gender are inconclusive, but on average slightly higher RTW chances for men have been reported. However, these personal factors cannot be changed in an intervention.

Modifiable personal factors that predict RTW according to the above mentioned reviews include: low self-esteem, feelings of hopelessness about the future, low social functioning, and recovery expectations such as self-efficacy. Recent longitudinal studies (published after the aforementioned reviews) confirm the role of work related self-efficacy as a robust RTW predictor in the heterogeneous population of employees with CMD [7][19][20][21].

Some personal factors seem of importance but are under-researched in longitudinal quantitative studies (and therefore not included in the abovementioned reviews). Several qualitative studies show the importance of personality characteristics (e.g. perfectionism, high sense of responsibility), work life-balance, the ability to set personal limits, and difficulty deciding the appropriate time to RTW as important factors for RTW (see, also for a more in depth discussion [22][23][24].

Environmental

With respect to work-related characteristics systematic reviews report that reorganizational stress, injury at work, unemployment threat, and lower pre-sick leave functioning at work reduce the chance for RTW. Among employees with mental disorders other than depression, RTW chances are higher when supervisors initiate frequent contact (e.g., once every 2 weeks) with non-depressed employees [9][10][11][12]

It may well be the case that other work related characteristics such as high mental work demands play a role in the RTW process, but work characteristics have not been studied that often. Qualitative research underlines, for example, organizational characteristics that complicate work adaptations during the RTW process and the influence of social support at the workplace (see 24 for a meta-analysis). Not all employers can or are willing to offer (temporary) work adaptations such as reduced work hours, workload or responsibilities. In addition, the workplace culture (e.g. with a strong focus of productivity and performance-oriented goals) can result in a suboptimal implementation of the accommodation agreements [25]. The importance of active support from the supervisor in the RTW process (e.g. facilitate work adjustments), has been identified as a strong predictor of successful RTW in quantitative studies as well [26].

Furthermore, one could presume that work characteristics needed to prevent the onset of sick leave due to mental health issues are of importance for a successful RTW (e.g., balanced work demands, decision latitude, and social support). The recent report from the international “Organisation for Economic Co-operation and Development (OECD)” stresses for example the importance of good management for mental health in the workplace. For example a line manager or supervisor who supports the worker, gives adequate feedback and recognizes the work effort is extremely important in facilitating the RTW process. In the study by Houtman and Blatter this was the most significant facilitator of RTW [26].

Beyond organizational factors, several governments from Western countries increasingly recognize the importance of effective policies and legislation that keep people with mental ill-health in employment. Regarding interventions the importance of activating disability policies is underlined: The requirements for both the benefit applicants and benefit authorities should be strengthened towards a focus on work capacities. Research across several European countries indeed shows that integrated disability policies (that focused on both the compensation of income and had a focus on reintegration) were more successful than welfare systems that focused on income replacement only, particularly for the low-educated ([12]; see also figure 1).

Other policy advise that can be found in the OECD reports is for example:

Improving skills and knowledge of general practitioners on mental health issues (e.g. diagnosis of CMD and inform them that prescribing “rest and being on sick leave” is potentially harmful to a patient with CMD).

Adapt systems and workplace policies in a way that the disclosure of a mental disorder is supported.

Reduction of the stigma on mental ill health might increase the willingness of employees to receive adequate care.

Evidence based interventions to enhance RTW

Usual treatment

It is estimated that about 80% of people with CMD will not receive any treatment [2]. If they do seek support they will mostly receive care from their general practitioner (GP). GP’s are, however, not sufficiently trained to deal with CMD’s leading to under diagnosis, inadequate treatment for symptom reduction, and stimulating sick leave as they generally prescribe patients ‘rest’ in combination with medical (non-work related) interventions [2][27][28].

A substantial part of employees on sick leave with CMD will receive clinical treatment from mental health professionals such as cognitive behavioral therapy or anti-depressants that successfully reduces complaints [29][30]. Although work is a central part of a people’s lives and an important element in recovery, standard clinical treatments for mental ill health pay little attention to work related problems [2][17][31]. For example, clinical guidelines or current clinical practice include no systematic approaches for employers (e.g. contacting them to inform about relevant workplace adaptations). Furthermore, mental health care quality indicators do not include any element of employment. Similar to GP’s most mental health care providers will adopt a symptom contingent approach. A focus on symptoms instead of resources can reinforce illness identity and non-work identity of the employees, which in turn can have a negative effect on the RTW process [24].

Some employees on sick leave will additionally receive support from occupational health providers (such as occupational physicians) or caseworkers from the employment and reintegration services. Information on the number of people with common mental disorders in such programmes and their effectiveness is very limited [2]. Not many vocational support services gather outcome data systematically that would allow evaluation of their services. Some of the effective interventions described below are, however, issued by professionals with more focus on work issues than GP’s or mental health providers (e.g. labour experts, occupational physicians, occupational therapists).

Finally, in nowadays practice cooperation and communication between the different stakeholders in the RTW process is not optimal and this might slow down the RTW process [24][27][32][33][34][34]. Stakeholders include for example the sick listed workers and their families, supervisors, healthcare providers, insurers and labor representatives. All stakeholders might have different views and –sometimes conflicting - interests in the RTW process. This can result in opposing advice, recommendations and demands that are difficult to deal with for an employee on sick leave: “This lack of coordination can cause a feeling of confusion and uncertainty about how and when to return to work” [24].

Effective RTW interventions

According to two reviews [35][36] it is hard to draw conclusions on what constitutes an effective RTW interventions for workers with CMD. The authors had to be cautious with conclusions because they had to draw them based on a few high quality studies (with a randomized controlled design that allows results to be attributed to the treatment with a high level of reliability) Below we incorporate research that is more recent than these reviews as well.

For depressed employees the following interventions are more effective to enhance RTW compared with other treatment. First, a combination of anti-depressant medication and psychodynamic therapy was more effective than mediation alone [35]. Secondly, work focused treatment (psychological and occupational therapy) resulted in more successful RTW [37][38] compared with usual care. For workers with adjustment disorders, Arends and colleagues [33] conclude that problem solving therapy can result in faster part-time resumption of work tasks (partial RTW).
In order to prevent the onset of mental health problems and related sick leave, organizational level interventions have been studied. However, for workers on sick leave due to CMD, no studies are available that describe (effective) RTW interventions targeted directly at the workplace or the organization. One study that included the most direct involvement of the workplace (a participatory workplace intervention) for employees with CMD, was however not effective [39].

A closer inspection of the RTW interventions that were effective compared to usual care [15][16][17][40] allows the identification of some elements that they have in common:

All interventions combined cognitive behavioral techniques with a focus on work. The work focus consisted of improving problem-solving coping or coping strategies related to return-to-work barriers.

In addition, there was a focus on graded RTW starting in an early phase of absenteeism (e.g. after 1-2 months even when symptoms had not fully recovered). In this way the contact with the workplace was restored as quickly as possible, in order to reduce the threshold for RTW. Graded RTW and early partial RTW are acknowledged by several authors as potential successful intervention elements [2][41][17][20]. However, there is a risk of subdividing the RTW process into (too) small steps. When an employee feels up to full RTW or larger RTW steps (e.g. has no fear of failure, is confident of implementing coping strategies), there is probably no need to follow a (highly) graded process. A study by Noordik that shares the aforementioned intervention elements for example was not effective, likely because it stimulated too small steps, while people did not need them [18].

A tailored RTW plan was drawn to guide the graded RTW process. This plan consists of a step by step approach that gradually increases work hours and task complexity until full RTW is achieved. This gradual approach (with work adjustments) can enhance success experiences when returning to work. Beneficial elements of work (e.g. social contact, structure, meaningful daily activity) are incorporated in the RTW plan in order to facilitate recovery.

All these interventions were targeted at the individual sick listed worker. Work place adaptations (e.g. reduced work hours, other tasks) were arranged as much as possible via the employee. However we have to note that the legislative context in which these interventions were offered often obliged employers to (actively) facilitate work adjustments. Several studies have stressed the importance of employers facilitating work adaptations for successful RTW [23][26] . In this way the mental health problem and sickness absence are not only interpreted as an individual problem that should be solved with individual adaption strategies, but that work place changes are also (temporarily) necessary.

The timing of the intervention seems to play a role as well. Research shows that early intervention and early partial RTW is important to reduce the threshold for RTW and avoid psychological complaints from becoming worse. Prolonged sick leave duration by itself seems to decrease the chances of RTW [12][42]. For example, those on sick leave for longer than 6 months were found to have only 50% chance to RTW [9]. The RTW chances decrease for those with a depression (mood disorder) when they are on sick leave for 3 months or more [42]. On the other hand, interventions should not be offered too early [2]. First of all, there is a risk of overtreatment. Offering an intervention too fast after the onset of sick leave might result in people postponing full RTW compared to a situation without treatment (risk of medicalization of the problem). In addition, people might need some weeks off from work as a coping strategy during a crisis phase.

Finally the type of intervention provider seems to matter. The evidence is inconclusive, but it seems that not all professionals are able to integrate work aspects. For an adequate work focus insight in workplace aspects and/ or RTW targets (e.g the professional is paid by the employer) seem to be necessary. For example, interventions that included promising elements (like problem solving and graded RTW) provided by General Practitioners (GP’s) or Social Workers were not effective, possibly because of their distance to the workplace. Insight and focus on work aspects can either follow by the nature of the profession (e.g. for labour experts, occupational therapist, occupational physicians) or by an elaborate work anamneses for those with a more distal relation to the employees’ workplace.

Effects of RTW interventions on mental health

Both employees and care providers express the concern that (early) RTW might evoke an increase of psychological symptoms. Hence, it is important to know what the effects of RTW interventions are on mental health. Several studies that describe effective RTW interventions have also reported on mental health outcomes. These studies show a decline of mental health problems over time, both for employees who received a RTW intervention and those who received regular care (e.g., [16][17][18]. As a reduction of mental health complaints occurred irrespective of treatment type, one can conclude that effective RTW interventions have no negative side effects on symptom reduction. For depressed patients effective RTW or stay at work interventions might even improve mental health [43][44].

Conclusion

It can be concluded that individual interventions with a focus on the workplace and RTW can enhance RTW. Effective ingredients of these interventions seem to be: active support of RTW from the supervisor; early graded RTW and activating cognitive behavioral therapy (CBT) based and/or problem solving techniques (e.g. learning coping skills to deal with RTW barriers). No clear evidence is available for the effectiveness of interventions directly targeted at the workplace.

↑ 12.012.112.212.312.412.512.6Stress Impact Consortium, Integrated report of Stress Impact: On the impact of changing social structures on stress and quality of life: Individual and social perspectives, Work package 8, Integrated report, August 2006.. Available at: [5]